Pharmacology & Toxicology Poster Session

Luana De Vito
devitos@axrma.uniroma1.it

>Great poster.  Is there any homologue or comparable vasoactive peptides to urotensins in higher organisms?  Also, you've identified a role for NO production in these fish- which in turn, regulates the production of these urotensins- NO in higher organisms, seems to function primarily as a vasodilator, some reports of vasoconstrictor effects (associated with peroxinitrite, maybe), seems like a complex issue in the fish, not as linear.  Any thoughts of NOS fish knockouts?!?!?

>Regards,
>Christopher Tan

Dr. Tan: Urotensin I (UI) shares a very close structural and bioactivity homology with sauvagine, a polypeptide isolated from the skin of the frog Phyllomedusa sauvagei, the hypothalamic corticotropin-releasing factor (CRF), and the mammalian urocortin, whereas urotensin II (UII) is structurally similar to mammalian somatostatin-14.
Nitric oxide has been shown to modulate neuronal function in both the peripheral and central nervous systems of mammals. In particular, both in vivo and in vitro experiments provide evidence for a neuromodulatory role of NO in the rat hypothalamo-neurohypophysial system, whereas a direct role for NO in the neuroendocrine regulation in lower vertebrates has not yet been verified. We have investigated the possible involvement of NO as neuromodulatory factor in fish neuroendocrine systems.
In our experiments fish were anaesthetized using a low concentration of MS222 (0,3 g/l).

Regards,
Luana De Vito (co-author of poster 656)